Tried Evapo-Rust.... It's, well, "kinda OK", I guess.

[J Tiers]

It seems to be like all the other methods, leaves a black coating on the steel, not all of which comes off. Not on all steels the same way, but there is some on any type I tried.

And it seems to etch the surface oddly... I de-rusted some taps, and the shanks are a different color dark gray from the cutting section, as if the E-R had done a "section etching", showing different steel types.

Yes, the bottles are labeled correctly, the stuff came from HF, and HF does carry the real Evapo-Rust as far as I know.

I really don't know that it is any better than phosphoric or even electrolytic derusting, although the electrolytic seems to produce a really hard black "shell", where phosphoric can leave a light gray coating that rubs off, and the Evapo-Rust seems to leave a black coating that is not a hard shell, but still does not all come off.

A lot of black dust rubbed off the EvapoRust parts, but they were still black after that.

Best result was on a pair of barber-type scissors, they were rusty from being in the bathroom a long time, and cleaned up with only a little of the black that would not come off. They ended up "grayish" but not black.

None of this sounds like the wonderful user reports and claims made about the Evapo-Rust, where the parts came out shiny and bright..

[reggie_obe]

Similar experience to JT.

Recently bought a gallon and tried it on the jaws and nut from a Rigid pipe wrench. Followed the directions, but was left with a dull grey finish that vigorous brushing only lightened a little.

[Doozer]

You are complaining about a black or grey color that is left
when the alternative is RUST? What is wrong with you ? ?
You need a genie in a bottle to make YOUR wishes come true.

-D

[CCWKen]

I rinse the parts, blow dry then take them over to the wire wheel machine (WWM). A course and/or fine once-over brings back the new metal shine.

[reggie_obe]

You are complaining about a black or grey color that is left
when the alternative is RUST? What is wrong with you ? ?
You need a genie in a bottle to make YOUR wishes come true.

-D

That what the maker claim Evaporust it to be. On an un-pitted, non-rusted area of a ground of machined surface, I expect a shine afterwards. Instead, those areas of the moveable jaw that had a high degree of finish, a shine, were dull.

[Baz]

Isn't ER the one that is chelate based rather than raw acid of some tiype? End result for all methods is very material and time dependent, with post treatment appearance aslo dependent on temperature and huidity too.
I think ER is the equivalent of WD40 in the oil arena - the mark up pays for the avertising for the non scientific customer to take confidence.

[J Tiers]

You are complaining about a black or grey color that is left
when the alternative is RUST? What is wrong with you ? ?
You need a genie in a bottle to make YOUR wishes come true.

-D

Oh, you ain't never gonna be happy. We just discount your comments 90%.

Point being that they sure enough claim wonderful results, but when you follow the directions, that is not what you get. And, as Reggie mentioned, it did something to the areas that were not at all rusted too, on several parts.

Hey, at least it is not actually WORSE than the other treatments, but considering that phosphoric is much cheaper per gallon, it looks like a better deal than EvapoRust. There should be some benefit to paying 4x more per gallon, but I am not seeing what all the hoopla is about.

The other thing is the folks here that were talking it up as if they were pulling out shiny metal parts that went in covered in rust. Naturally I did not believe THAT, but nobody seems to have said much about the black coating that appears.

I'm thinking I'll need to use "muriatic" acid to finish the clean-up (hydrochloric)

[Bob La Londe]

I can tell you that its very hard to read the labeling on reamers that have been cleaned up with evaporust. I got a bunch of them a while back that still had the flutes covered in wax, but shanks were rusty.

[Ringo]

I derusted some BBQ grill grates with plain vinegar, yes also the dark coating was left, but it rinsed off easily with water & wire brush, nearly white metal was the result.

[livesteam]

Be very careful when using phosphoric acid on tools and hardened metals. Anything under tension is prone to break.
It has happened to me. Read up on hydrogen embrittlement: https://en.wikipedia.org/wiki/Hydrogen_embrittlement

[lakeside53]

I pull out shiny parts all the time. But... it depends. Evaporust will show the hardened high carbon steels as a darker color. Mild steels - shiny (after gentle washing). ER says it's the carbon you are seeing - it's not a coating.

As for the benefits - as we've all discussed a zillion times.. every technique has its place. I find ER works especially well with mixed metals like motor rotors, stators etc, or anything you don't want an acid near or residual coating on.

If you REALLY want ER to excel, put it an ultrasonic cleaner and keep it above 100F.

[lakeside53]

Be very careful when using phosphoric acid on tools and hardened metals. Anything under tension is prone to break.
It has happened to me. Read up on hydrogen embrittlement: https://en.wikipedia.org/wiki/Hydrogen_embrittlement

Oh boy, you had to go there 😂

[J Tiers]

Be very careful when using phosphoric acid on tools and hardened metals. Anything under tension is prone to break.
It has happened to me. Read up on hydrogen embrittlement: https://en.wikipedia.org/wiki/Hydrogen_embrittlement

You are late to the party.... I have commented on that before (and got a few nasty comments for my trouble). Electrolytic method seems to have the exact same issue, and it is quite possible that evapo-rust does as well.

It's not hydrogen embrittlement, though, it is stress corrosion cracking.

[nickel-city-fab]

I derusted some BBQ grill grates with plain vinegar, yes also the dark coating was left, but it rinsed off easily with water & wire brush, nearly white metal was the result.

Thats how I do it too, and I've had very good luck that way. Can't beat the price of vinegar. After the vinegar soak, I boil the parts in a solution of baking soda to neutralize it. Pull em out of the pot and they go straight into the kerosene while they're still hot. Frees things right up and you would never know how bad they had been.

I've rescued tools that I found in fields and in the middle of the road after a long salty winter that way. The chrome doesn't come back, but everything else does.

[Tungsten dipper]

Yep! That Evaporust is horrible stuff.